The subject matter disclosed herein generally relates to cooling chambers in components of gas turbine engines and, more particularly, to an improved cooling chamber of a component of a gas turbine engine.
Gas turbine engines are known and typically include a compressor section compressing air and delivering it into a combustion section. The air is mixed with fuel in the combustion section and ignited. Products of the combustion pass downstream over turbine rotors, driving the turbine rotors.
A number of components are utilized in gas turbine engines to control the flow of the products of combustion such that they are directed along desired flow paths. One such component is called a blade outer air seal. A blade outer air seal sits slightly radially outwardly of an outer tip of a turbine blade in a turbine rotor, which is driven to rotate by the products of combustion. By having the blade outer air seal closely spaced from the rotor, leakage of the products of combustion around the turbine rotor is reduced.
The blade outer air seals are subject to very high temperature. Thus, cooling air may be supplied through the blade outer air seal to counter the high temperature. Cooling air from a source of air cooler than the product of combustion is circulated through channels in the blade outer air seal. The channels may be thin in a radial dimension. As the channel becomes thinner relative to an axial width of the channel, the flow characteristics of the cooling air may degrade. That is, when an aspect ratio of a circumferentially-flowing channel (where the aspect ratio is the radial dimension divided by the axial dimension), is relatively high, then there is good circulation of air and desirable heat transfer characteristics. On the other hand, as the aspect ratio drops, which occurs as the (radial) height of the channel becomes smaller, the heat transfer effectiveness may decrease and/or friction losses may increase. Having a thinner radial dimension is desirable to enable higher cooling effectiveness for the same amount of air flow, or achieving the same cooling effectiveness with reduced air flow.
Multiple channels may be arranged adjacent to each other, around a circumference of a rotor or other disk that includes airfoils. To maintain consistent heat flux along the length of the channel, in the airflow direction, the channel may have a tapered width, i.e., a direction normal to the airflow direction.
An aspect ratio of a circumferentially-flowing channel (where the aspect ratio is the radial dimension divided by the axial dimension, i.e., channel height divided by channel width), is relatively high, then there is good circulation of air and desirable heat transfer characteristics. On the other hand, as the aspect ratio drops, which occurs as the (radial) height of the channel becomes smaller, the heat transfer effectiveness may decrease and/or friction losses may increase. Having a thinner radial dimension is desirable to enable higher cooling effectiveness for the same amount of air flow, or achieving the same cooling effectiveness with reduced air flow. In certain situations, there may be minimum and maximum allowed height-to-width ratios, due to tolerances and forces imposed on the disks during operation. Accordingly, high tapering angles, e.g., channels with large widths, may be difficult to implement. Thus, improved multi-flow chambers for cooling that enable large channel widths and low heights is desirable.